Humidity control apparatus

ABSTRACT

A first adsorption heat exchanger ( 51 ) and a second adsorption heat exchanger ( 52 ) are provided in a refrigerant circuit ( 50 ) of a humidity control apparatus ( 10 ). In the refrigerant circuit ( 50 ), a refrigerant circulation direction can be reversed. In a purge operation of the humidity control apparatus ( 10 ), each of actions is performed, which are a purge action in which the first adsorption heat exchanger ( 51 ) serves as an evaporator, and a purge action in which the second adsorption heat exchanger ( 52 ) serves as the evaporator. During the purge operation, outdoor air is sent to the adsorption heat exchanger ( 51, 52 ) serving as the evaporator, and moisture in the outdoor air adsorbs to the adsorption heat exchanger ( 51, 52 ). A moisture content of the adsorption heat exchanger ( 51, 52 ) during the purge operation is greater than that during a normal operation, and odor material adsorbed to the adsorption heat exchanger ( 51, 52 ) is removed by moisture adsorbed to the adsorption heat exchanger ( 51, 52 ) during the purge operation.

TECHNICAL FIELD

The present invention is relates to a humidity control apparatus forcontrolling air humidity by using adsorbent.

BACKGROUND ART

Conventionally, humidity control apparatuses are known, which controlair humidity by using adsorbent. Patent Document 1 discloses a humiditycontrol apparatus including adsorption heat exchangers with adsorbentdeposited on surfaces thereof.

The humidity control apparatus disclosed in Patent Document 1 includes arefrigerant circuit with two adsorption heat exchangers. The refrigerantcircuit alternately performs an action in which the first adsorptionheat exchanger serves as a condenser, and the second adsorption heatexchanger serves as an evaporator; and an action in which the secondadsorption heat exchanger serves as the condenser, and the firstadsorption heat exchanger serves as the evaporator. In the adsorptionheat exchanger operating as the evaporator, moisture in air adsorbs tothe adsorbent. In the adsorption heat exchanger operating as thecondenser, moisture desorbs from the adsorbent to be imparted to air.

The humidity control apparatus disclosed in Patent Document 1 supplies apart of air passing through the adsorption heat exchangers to a room,and discharges the remaining air to outside. During a dehumidificationoperation, in the humidity control apparatus, air passing through one ofthe first and second adsorption heat exchangers, which operates as theevaporator, is supplied to the room; and air passing through the otheradsorption heat exchanger which operates as the condenser is dischargedto the outside. During a humidification operation, in the humiditycontrol apparatus, air passing through one of the first and secondadsorption heat exchangers, which operates as the evaporator, isdischarged to the outside; and air passing through the other adsorptionheat exchanger which operates as the condenser is supplied to the room.

CITATION LIST Patent Document

PATENT DOCUMENT 1: Japanese Patent Publication No. 2006-078108

SUMMARY OF THE INVENTION Technical Problem

During an operation of the humidity control apparatus, not only moisture(water vapor) in air but also odor material such as ammonia adsorb tothe adsorbent. During the operation of the humidity control apparatus,such odor material is accumulated in the adsorbent. Depending on anoperating condition of the humidity control apparatus, the odor materialmay desorb from the adsorbent to be sent to the room together with thehumidity-controlled air, thereby causing a loss of comfort in the room.

The present invention has been made in view of the foregoing, and it isan object of the present invention to remove the odor material from theadsorbent by the operation of the humidity control apparatus in thehumidity control apparatus using the adsorbent.

Solution to the Problem

A first aspect of the invention is intended for a humidity controlapparatus including adsorption members (51, 52) with adsorbent, andcontrolling air humidity by exposing taken air to the adsorbent of theadsorption members (51, 52). Operations are selectively executed, whichare normal operations in which air, humidity of which is controlled whenpassing through the adsorption member (51, 52), is supplied to a room;and a purge operation in which, in order to desorb odor material fromthe adsorption member (51, 52), moisture in taken air adsorbs to theadsorption member (51, 52) to obtain a moisture content of theadsorption member (51, 52) equal to or greater than a maximum value of amoisture content of the adsorption member (51, 52) during the normaloperation.

In the first aspect of the invention, the normal operations and thepurge operation are performed in the humidity control apparatus (10).During the normal operations, the humidity control apparatus (10)supplies taken air to the adsorption member (51, 52), and supplies airdehumidified or humidified by exposing to the adsorption member (51, 52)to the room. During the purge operation, the humidity control apparatus(10) supplies taken air to the adsorption member (51, 52), and moisturein air adsorbs to the adsorption member (51, 52).

In the first aspect of the invention, during the purge operation, themoisture content of the adsorption member (51, 52) (i.e., amount of H₂Oadsorbed to the adsorption member (51, 52)) increases. As the moisturecontent of the adsorption member (51, 52) increases, odor material whichhas been adsorbed to the adsorbent is removed by water adsorbed to theadsorbent later, and then desorbs from the adsorbent. This reduces theamount of odor material adsorbed to the adsorption member (51, 52) whenincreasing the moisture content of the adsorption member (51, 52) byperforming the purge operation.

In addition, during the purge operation of the first aspect of theinvention, the moisture content of the adsorption member (51, 52)reaches the value equal to or greater than the moisture content of theadsorption member (51, 52) during the normal operation. Thus, during thenormal operation subsequent to the purge operation, the moisture contentof the adsorption member (51, 52) does not exceed the value during thepurge operation, thereby reducing desorption of odor material from theadsorption member (51, 52).

A second aspect of the invention is intended for the humidity controlapparatus of the first aspect of the invention, in which adsorption heatexchangers (51, 52) with adsorbent deposited on surfaces thereof areprovided as the adsorption members; the adsorption heat exchangers (51,52) are connected to each other to form a heat-transfer medium circuit(50) in which heat-transfer medium circulates; and the heat-transfermedium circuit (50) performs an action in which heat-transfer medium forcooling is supplied to the adsorption heat exchanger (51, 52) in orderto adsorb moisture in air to the adsorption heat exchanger (51, 52), andan action in which heat-transfer medium for heating is supplied to theadsorption heat exchanger (51, 52) in order to desorb moisture from theadsorption heat exchanger (51, 52).

In the second aspect of the invention, the adsorption heat exchangers(51, 52) are provided as the adsorption members in the humidity controlapparatus (10). In the adsorption heat exchanger (51, 52) to which theheat-transfer medium for cooling is supplied, moisture in air adsorbs tothe adsorbent deposited on the surface thereof, and adsorption heatgenerated thereupon is absorbed by the heat-transfer medium for cooling.On the other hand, in the adsorption heat exchanger (51, 52) to whichthe heat-transfer medium for heating is supplied, the adsorbentdeposited on the surface thereof is heated by the heat-transfer mediumfor heating, and moisture desorbed from the heated adsorbent is impartedto air passing through the adsorption heat exchanger (51, 52).

A third aspect of the invention is intended for the humidity controlapparatus of the second aspect of the invention, in which a refrigerantcircuit (50) performing a refrigeration cycle by circulating refrigerantis provided as the heat-transfer medium circuit; and, during the purgeoperation, in the refrigerant circuit (50), refrigerant circulates sothat the adsorption heat exchanger (51, 52) to which moisture in airadsorbs serves as an evaporator, and a capacity of a compressor (53) iscontrolled so that a refrigerant evaporation temperature in theadsorption heat exchanger (51, 52) is equal to a dew-point temperatureof air passing through the adsorption heat exchanger (51, 52).

In the third aspect of the invention, the refrigerant circuit (50) isprovided as the heat-transfer medium circuit in the humidity controlapparatus (10). In the refrigerant circuit (50), high-pressurerefrigerant is supplied to the adsorption heat exchanger (51, 52) as theheat-transfer medium for heating, and low-pressure refrigerant issupplied to the adsorption heat exchanger (51, 52) as the heat-transfermedium for cooling. In the adsorption heat exchanger (51, 52) to whichmoisture in air adsorbs during the purge operation, the suppliedlow-pressure refrigerant absorbs the adsorption heat to be evaporated.

In the third aspect of the invention, during the purge operation, thecapacity of the compressor (53) is controlled in the refrigerant circuit(50) so that the refrigerant evaporation temperature in the adsorptionheat exchanger (51, 52) operating as the evaporator is equal to thedew-point temperature of air passing through the adsorption heatexchanger (51, 52). The surface temperature of the adsorption heatexchanger (51, 52) rises to some extent as compared to the refrigerantevaporation temperature in the adsorption heat exchanger (51, 52). Thatis, the surface temperature of the adsorption heat exchanger (51, 52) isslightly higher than the dew-point temperature of air passing throughthe adsorption heat exchanger (51, 52). This does not cause condensationof moisture in air on the surface of the adsorption heat exchanger (51,52) serving as the evaporator during the purge operation.

A fourth aspect of the invention is intended for the humidity controlapparatus of the third aspect of the invention, in which, during thepurge operation, in the refrigerant circuit (50), a degree of opening ofan expansion valve (55) is controlled so that a degree of superheat ofrefrigerant at an outlet of the adsorption heat exchanger (51, 52)serving as the evaporator is constant.

In the fourth aspect of the invention, the degree of opening of theexpansion valve (55) during the purge operation is controlled so thatthe degree of superheat of refrigerant flowing out from the adsorptionheat exchanger (51, 52) serving as the evaporator is constant.

A fifth aspect of the invention is intended for the humidity controlapparatus of the second aspect of the invention, in which a refrigerantcircuit (50) performing a refrigeration cycle by circulating refrigerantis provided as the heat-transfer medium circuit; the refrigerant circuit(50) includes a first adsorption heat exchanger (51) and a secondadsorption heat exchanger (52) as adsorption members, and is switchablebetween a state in which the first adsorption heat exchanger (51) servesas a heat radiator, and the second adsorption heat exchanger (52) servesas the evaporator; and a state in which the second adsorption heatexchanger (52) serves as the heat radiator, and the first adsorptionheat exchanger (51) serves as the evaporator; during the normaloperation, actions are alternately repeated, which are a first normalaction in which second air is supplied to the first adsorption heatexchanger (51) serving as the heat radiator, and first air is suppliedto the second adsorption heat exchanger (52) serving as the evaporator,and a second normal action in which second air is supplied to the secondadsorption heat exchanger (52) serving as the heat radiator, and firstair is supplied to the first adsorption heat exchanger (51) serving asthe evaporator; and one of the first dehumidified air and the secondhumidified air is supplied to the room, and the other is discharged tooutside; and during the purge operation, each of actions is performed,which are a first purge action in which outdoor air is supplied to thefirst adsorption heat exchanger (51) serving as the heat radiator, andto the second adsorption heat exchanger (52) serving as the evaporator,and a second purge action in which outdoor air is supplied to the secondadsorption heat exchanger (52) serving as the heat radiator, and to thefirst adsorption heat exchanger (51) serving as the evaporator; and theoutdoor air passing through the first adsorption heat exchanger (51) andthe second adsorption heat exchanger (52) is discharged to the outside.

In the fifth aspect of the invention, the first adsorption heatexchanger (51) and the second adsorption heat exchanger (52) areconnected to each other as the adsorption members in the refrigerantcircuit (50). The refrigerant circuit (50) performs the refrigerationcycle by circulating refrigerant. At this point, in the refrigerantcircuit (50), refrigerant releases heat in one of the first adsorptionheat exchanger (51) and the second adsorption heat exchanger (52),refrigerant absorbs heat in the other.

In the fifth aspect of the invention, during the normal operation, thehumidity control apparatus (10) alternately repeats the first and secondnormal actions. That is, in the normal operation, each of the firstadsorption heat exchanger (51) and the second adsorption heat exchanger(52) alternately performs the action for adsorbing moisture in the firstair, and the action for imparting desorbed moisture to the second air.

In addition, in the fifth aspect of the invention, during the purgeoperation, the humidity control apparatus (10) performs each of thefirst and second purge actions. In the first purge action, moisture inoutdoor air adsorbs to the second adsorption heat exchanger (52) servingas the evaporator to remove odor material from the second adsorptionheat exchanger (52), and refrigerant releases heat to outdoor air in thefirst adsorption heat exchanger (51). On the other hand, in the secondpurge action, moisture in outdoor air adsorbs to the first adsorptionheat exchanger (51) serving as the evaporator to remove odor materialfrom the first adsorption heat exchanger (51), and refrigerant releasesheat to outdoor air in the second adsorption heat exchanger (52). Duringthe purge operation, outdoor air passing through the first adsorptionheat exchanger (51) and the second adsorption heat exchanger (52) isdischarged to the outside.

A sixth aspect of the invention is intended for the humidity controlapparatus of the fifth aspect of the invention, in which the first andsecond normal actions are alternately performed at predetermined timeintervals during the normal operation; the first and second purgeactions are performed for a predetermined period of time during thepurge operation; and a duration time of each purge action during thepurge operation is longer than a duration time of each normal actionduring the normal operation.

In the sixth aspect of the invention, each of the purge actions of thepurge operation is performed for a longer period of time than eachnormal action of the normal operation. That is, during the purgeoperation, moisture in outdoor air continuously adsorbs to theadsorption heat exchanger (51, 52) for a longer period of time ascompared to the normal operation.

A seventh aspect of the invention is intended for the humidity controlapparatus of the first aspect of the invention, in which a duration timeof the purge operation is controlled so as to increase as an absolutehumidity of air supplied to the adsorption member (51, 52) during thepurge operation becomes lower.

In the seventh aspect of the invention, the duration time of the purgeoperation is controlled depending on the absolute humidity of airpassing through the adsorption member (51, 52). When decreasing theabsolute humidity of air supplied to the adsorption member (51, 52),moisture in air poorly adsorbs to the adsorption member (51, 52). Thus,time required for sufficiently increasing the moisture content of theadsorption member (51, 52) becomes longer, thereby extending theduration time of the purge operation. Conversely, when increasing theabsolute humidity of air supplied to the adsorption member (51, 52),moisture in air easily adsorbs to the adsorption member (51, 52). Thus,the time required for sufficiently increasing the moisture content ofthe adsorption member (51, 52) becomes shorter, thereby shortening theduration time of the purge operation.

A eighth aspect of the invention is intended for the humidity controlapparatus of the first aspect of the invention, in which the purgeoperation is performed every time a summation of time for which thenormal operations are performed reaches a predetermined reference value.

In the eighth aspect of the invention, the purge operation is performedevery time the normal operation is performed for a predetermined periodof time, and odor material accumulated in the adsorption member (51, 52)during the normal operation is removed from the adsorption member (51,52).

ADVANTAGES OF THE INVENTION

According to the present invention, the humidity control apparatus (10)performs the purge operation to increase the moisture content of theadsorption member (51, 52), thereby desorbing odor material from theadsorption member (51, 52). The amount of odor material adsorbed to theadsorption member (51, 52) can be reduced by the operation of thehumidity control apparatus (10) itself without a maintenance persongoing and working at an installation site of the humidity controlapparatus (10). This prevents odor material desorbed from the adsorptionmembers (51, 52) from being supplied to the room together withhumidity-controlled air during the normal operations, thereby ensuringimprovement of comfort in the room.

During the purge operation of the present embodiment, the moisturecontent of the adsorption member (51, 52) reaches the value equal to orgreater than the moisture content of the adsorption member (51, 52)during the normal operation. That is, during the normal operationsubsequent to the purge operation, the moisture content of theadsorption member (51, 52) does not exceed the value during the purgeoperation. This ensures reduction of desorption of odor material fromthe adsorption members (51, 52) during the normal operations, thereby,also in this regard, ensuring the comfort in the room.

In the third aspect of the invention, the capacity of the compressor(53) of the refrigerant circuit (50) is controlled so that therefrigerant evaporation temperature in the adsorption heat exchanger(51, 52) operating as the evaporator during the purge operation is equalto the dew-point temperature of air passing through such an adsorptionheat exchanger (51, 52). This reduces the surface temperature of theadsorption heat exchanger (51, 52) as much as possible within a range inwhich dew condensation is not caused on the surface of the adsorptionheat exchanger (51, 52) serving as the evaporator, during the purgeoperation. Consequently, it is unnecessary to dispose drain water due tothe dew condensation on the adsorption heat exchanger (51, 52), and theamount of moisture adsorbed to the adsorption heat exchanger (51, 52)during the purge operation can be maximized.

In the fifth aspect of the invention, during the purge operation, thehumidity control apparatus (10) supplies outdoor air to the firstadsorption heat exchanger (51) and the second adsorption heat exchanger(52), and discharges the outdoor air passing through the adsorption heatexchangers (51, 52) to the outside. That is, the humidity controlapparatus (10) performs the purge operation without sucking air from theroom, and blowing off air to the room. Thus, according to the presentinvention, the purge operation can be performed without effects on theroom environment.

In the sixth aspect of the invention, the time for which moisture in airadsorbs to the adsorption heat exchanger (51, 52) during the purgeoperation is longer than the time for which moisture in air adsorbs tothe adsorption heat exchanger (51, 52) during the normal operation.Thus, according to the present invention, this ensures the moisturecontent of the adsorption heat exchanger (51, 52) during the purgeoperation, which is greater than the moisture content of the adsorptionheat exchanger (51, 52) during the normal operation, thereby ensuringremoval of odor material from the adsorption heat exchanger (51, 52) bythe purge operation.

In the seventh aspect of the invention, the duration time of the purgeoperation is controlled depending on the absolute humidity of air fromwhich moisture is imparted to the adsorption member (51, 52) during thepurge operation. This ensures an increase in the moisture content of theadsorption member (51, 52) in spite of the air state during the purgeoperation, thereby ensuring the removal of odor material from theadsorption member (51, 52).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a humidity control apparatus as viewedfrom a frontal side, which is illustrated without a top plate of acasing.

FIG. 2 is a perspective view of the humidity control apparatus as viewedfrom the frontal side, which is illustrated without a part of the casingand an electrical component box.

FIG. 3 is a plan view of the humidity control apparatus, which isillustrated without the top plate of the casing.

FIG. 4 are schematic plan, right side, and left side views which areillustrated without a part of the humidity control apparatus.

FIG. 5 are plumbing diagrams illustrating a structure of a refrigerantcircuit. FIG. 5(A) illustrates a first normal action and a first purgeaction. FIG. 5(B) illustrates a second normal action and a second purgeaction.

FIG. 6 are schematic plan, right side, and left side views of thehumidity control apparatus, which illustrate an air flow in a firstnormal action of a dehumidification/ventilation operation.

FIG. 7 are schematic plan, right side, and left side views of thehumidity control apparatus, which illustrate an air flow in a secondnormal action of the dehumidification/ventilation operation.

FIG. 8 are schematic plan, right side, and left side views of thehumidity control apparatus, which illustrate an air flow in a firstnormal action of a humidification/ventilation operation.

FIG. 9 are schematic plan, right side, and left side views of thehumidity control apparatus, which illustrate an air flow in a secondnormal action of the humidification/ventilation operation.

FIG. 10 are schematic plan, right side, and left side views of thehumidity control apparatus, which illustrate an air flow in a simpleventilation operation.

FIG. 11 are schematic plan, right side, and left side views of thehumidity control apparatus, which illustrate an air flow in a purgeoperation.

FIG. 12 are schematic plan, right side, and left side views of thehumidity control apparatus, which illustrate an air flow in the purgeoperation.

FIG. 13 is a flow chart of a control operation of a controller in thepurge operation.

DESCRIPTION OF REFERENCE CHARACTERS

-   10 Humidity control apparatus-   50 Refrigerant Circuit (Heat-Transfer Medium Circuit)-   51 First Adsorption Heat Exchanger (Adsorption Member)-   52 Second Adsorption Heat Exchanger (Adsorption Member)-   60 Controller

DESCRIPTION OF EMBODIMENTS

An embodiment of the present invention will be described in detailhereinafter with reference to the drawings. A humidity control apparatus(10) of the present embodiment is for controlling humidity in a room,and ventilating the room. The humidity control apparatus (10) controlsthe humidity of taken outdoor air (OA) to supply such air to the room,and, at the same time, discharges taken room air (RA) to outside.

<Entire Structure of Humidity Control Apparatus>

The humidity control apparatus (10) will be described with reference toFIGS. 1-4 as necessary. Unless otherwise specified, terms “upper,”“lower,” “left,” “right,” “front,” “rear,” “near,” and “back” usedherein designate directions when the humidity control apparatus (10) isviewed from a frontal side.

The humidity control apparatus (10) includes a casing (11). Arefrigerant circuit (50) is accommodated in the casing (11). In therefrigerant circuit (50), a first adsorption heat exchanger (51), asecond adsorption heat exchanger (52), a compressor (53), a four-wayswitching valve (54), and an electric-operated expansion valve (55) areconnected to each other. The refrigerant circuit (50) will be describedin detail later.

The casing (11) is formed in an approximately-flatrectangular-parallelepiped shape with a relatively-low height. In thecasing (11) illustrated in FIG. 2, a side surface on a near-left side(i.e., frontal surface) serves as a frontal panel section (12); a sidesurface on a back-right side (i.e., dorsal surface) serves as a dorsalpanel section (13); a side surface on a near-right side serves as afirst side panel section (14); and a side surface on a back-left sideserves as a second side panel section (15).

The casing (11) includes an outdoor air suction port (24); a room airsuction port (23); an air supply port (22); and an air discharge port(21). The outdoor air suction port (24) and the room air suction port(23) open in the dorsal panel section (13). The outdoor air suction port(24) is arranged in a lower portion of the dorsal panel section (13).The room air suction port (23) is arranged in an upper portion of thedorsal panel section (13). The air supply port (22) is arranged close toan end portion of the first side panel section (14) on the frontal panelsection (12) side. The air discharge port (21) is arranged close to anend portion of the second side panel section (15) on the frontal panelsection (12) side.

An inner space of the casing (11) includes an upstream partition plate(71); a downstream partition plate (72); a central partition plate (73);a first partition plate (74); and a second partition plate (75). Thepartition plates (71-75) are vertically arranged on a bottom plate ofthe casing (11), and extend from the bottom plate to an top plate of thecasing (11) to divide the inner space of the casing (11).

The upstream partition plate (71) and the downstream partition plate(72) are arranged at predetermined intervals in a front-rear directionof the casing (11) so as to be parallel to the frontal panel section(12) and the dorsal panel section (13). The upstream partition plate(71) is arranged closer to the dorsal panel section (13). The downstreampartition plate (72) is arranged closer to the frontal panel section(12).

The first partition plate (74) and the second partition plate (75) arearranged so as to be parallel to the first side panel section (14) andthe second side panel section (15). The first partition plate (74) isarranged at a predetermined interval from the first side panel section(14) so as to close a space between the upstream partition plate (71)and the downstream partition plate (72) from the right side. The secondpartition plate (75) is arranged at a predetermined interval from thesecond side panel section (15) so as to close the space between theupstream partition plate (71) and the downstream partition plate (72)from the left side.

The central partition plate (73) is arranged between the upstreampartition plate (71) and the downstream partition plate (72) so as to beperpendicular to the upstream partition plate (71) and the downstreampartition plate (72). The central partition plate (73) is provided so asto extend from the upstream partition plate (71) to the downstreampartition plate (72), and divides the space between the upstreampartition plate (71) and the downstream partition plate (72) into rightand left spaces.

In the casing (11), a space between the upstream partition plate (71)and the dorsal panel section (13) is divided into two upper and lowerspaces. The upper space defines a room air path (32), and the lowerspace defines an outdoor air path (34). The room air path (32)communicates with the room through a duct connected to the room airsuction port (23). In the room air path (32), a room air filter (27), aroom air humidity sensor (96), and a room air temperature sensor areinstalled. The outdoor air path (34) communicates with an outdoor spacethrough a duct connected to the outdoor air suction port (24). In theoutdoor air path (34), an outdoor air filter (28), an outdoor airhumidity sensor (97), and an outdoor air temperature sensor areinstalled. The room air humidity sensor (96) and the outdoor airhumidity sensor (97) measure air relative humidity. The room airtemperature sensor and the outdoor air temperature sensor are omitted inthe figures.

The space between the upstream partition plate (71) and the downstreampartition plate (72) in the casing (11) is divided into the right andleft spaces by the central partition plate (73). The right space withrespect to the central partition plate (73) serves as a first heatexchange chamber (37), and the left space with respect to the centralpartition plate (73) serves as a second heat exchange chamber (38). Thefirst adsorption heat exchanger (51) is accommodated in the first heatexchange chamber (37). The second adsorption heat exchanger (52) isaccommodated in the second heat exchange chamber (38). Although notillustrated in the figure, the electric-operated expansion valve (55) ofthe refrigerant circuit (50) is accommodated in the first heat exchangechamber (37).

The adsorption heat exchangers (51, 52) serve as adsorption members forexposing the adsorbent to air. Each of the adsorption heat exchangers(51, 52) is a so-called “cross-fin-type fin-and-tube heat exchanger”with adsorbent deposited on a surface thereof, and is formed in a thickrectangular plate-like shape or a flat rectangular-parallelepiped shapeas a whole. The adsorption heat exchangers (51, 52) are verticallyarranged in the heat exchange chambers (37, 38) so that frontal anddorsal surfaces thereof are parallel to the upstream partition plate(71) and the downstream partition plate (72). As the adsorbent depositedon the adsorption heat exchangers (51, 52), e.g., zeolite, silica gel,etc., or a mixture thereof is used.

In the inner space of the casing (11), a space along a frontal surfaceof the downstream partition plate (72) is divided into upper and lowerspaces. The upper portion of the horizontally-divided spaces defines anair supply path (31), and the lower portion defines an air dischargepath (33).

Four openable dampers (41-44) are provided in the upstream partitionplate (71). Each of the dampers (41-44) is formed in an approximatelyhorizontally-elongated rectangular shape. Specifically, in a portion(upper portion) of the upstream partition plate (71), which faces theroom air path (32), a first room air damper (41) is attached on theright side with respect to the central partition plate (73), and asecond room air damper (42) is attached on the left side with respect tothe central partition plate (73). In a portion (lower portion) of theupstream partition plate (71), which faces the outdoor air path (34), afirst outdoor air damper (43) is attached on the right side with respectto the central partition plate (73), and a second outdoor air damper(44) is attached on the left side with respect to the central partitionplate (73).

Four openable dampers (45-48) are provided in the downstream partitionplate (72). Each of the dampers (45-48) is formed in an approximatelyhorizontally-elongated rectangular shape. Specifically, in a portion(upper portion) of the downstream partition plate (72), which faces theair supply path (31), a first air supply damper (45) is attached on theright side with respect to the central partition plate (73), and asecond air supply damper (46) is attached on the left side with respectto the central partition plate (73). In a portion (lower portion) of thedownstream partition plate (72), which faces the air discharge path(33), a first air discharge damper (47) is attached on the right sidewith respect to the central partition plate (73), and a second airdischarge damper (48) is attached on the left side with respect to thecentral partition plate (73).

In the casing (11), a space between the air supply path (31) and the airdischarge path (33), and the frontal panel section (12) is divided intoright and left spaces by a partition plate (77). The right space withrespect to the partition plate (77) defines an air supply fan chamber(36), and the left space with respect to the partition plate (77)defines an air discharge fan chamber (35).

An air supply fan (26) is accommodated in the air supply fan chamber(36). An air discharge fan (25) is accommodated in the air discharge fanchamber (35). The air supply fan (26) and the air discharge fan (25) arecentrifugal multi-blade fans (so-called “sirocco” fans).

Specifically, such fans (25, 26) includes fan rotors; fan casings (86);and fan motors (89). Although not illustrated in the figures, the fanrotor is formed in a cylindrical shape, the length of which in an axialdirection is shorter than its diameter, and many impellers are formed ina circumferential surface of the fan rotor. The fan rotor isaccommodated in the fan casing (86). An intake port (87) opens at one ofside surfaces (side surfaces perpendicular to the axial direction of thefan rotor) of the fan casing (86). In addition, a portion outwardlyprotruding from a circumferential surface of the fan casing (86) isformed in the fan casing (86), and a blow-off port (88) opens at an endportion of the protrusion. The fan motor (89) is attached to a surfaceon a side of the fan casing (86), which is opposite to the intake port(87) side. The fan motor (89) is connected to the fan rotor to rotatablydrive the fan rotor.

When rotatably driving the fan rotors by the fan motors (89) in the airsupply fan (26) and the air discharge fan (25), air is sucked into thefan casings (86) through the intake ports (87), and air in the fancasings (86) is blown off through the blow-off ports (88).

In the air supply fan chamber (36), the air supply fan (26) is installedso that the intake port (87) of the fan casing (86) faces the downstreampartition plate (72). In addition, the blow-off port (88) of the fancasing (86) of the air supply fan (26) is attached to the first sidepanel section (14) so as to communicate with the air supply port (22).

In the air discharge fan chamber (35), the air discharge fan (25) isinstalled so that the intake port (87) of the fan casing (86) faces thedownstream partition plate (72). In addition, the blow-off port (88) ofthe fan casing (86) of the air discharge fan (25) is attached to thesecond side panel section (15) so as to communicate with the airdischarge port (21).

The compressor (53) and the four-way switching valve (54) of therefrigerant circuit (50) are accommodated in the air supply fan chamber(36). The compressor (53) and the four-way switching valve (54) arearranged between the air supply fan (26) and the partition plate (77) inthe air supply fan chamber (36).

In the casing (11), a space between the first partition plate (74) andthe first side panel section (14) defines a first bypass path (81). Astart point of the first bypass path (81) communicates only with theoutdoor air path (34), and is isolated from the room air path (32). Aterminal point of the first bypass path (81) is separated from the airsupply path (31), the air discharge path (33), and the air supply fanchamber (36) by a partition plate (78). A portion of the partition plate(78), which faces the air supply fan chamber (36), is provided with afirst bypass damper (83).

In the casing (11), a space between the second partition plate (75) andthe second side panel section (15) defines a second bypass path (82). Astart point of the second bypass path (82) communicates only with theroom air path (32), and is isolated from the outdoor air path (34). Aterminal point of the second bypass path (82) is separated from the airsupply path (31), the air discharge path (33), and the air discharge fanchamber (35) by a partition plate (79). A portion of the partition plate(79), which faces the air discharge fan chamber (35), is provided with asecond bypass damper (84).

The right and left side views of FIG. 4 are illustrated without thefirst bypass path (81), the second bypass path (82), the first bypassdamper (83), and the second bypass damper (84).

In the frontal panel section (12) of the casing (11), an electricalcomponent box (90) is attached to a portion closer to the right of thefrontal panel section (12). In FIGS. 2 and 4, the electrical componentbox (90) is omitted. The electrical component box (90) is arectangular-parallelepiped box, and a control substrate (91) and apower-source substrate (92) are accommodated therein. The controlsubstrate (91) and the power-source substrate (92) are attached to aninner surface in a portion of a side plate of the electrical componentbox (90), which is adjacent to the frontal panel section (12).Heat-release fins (93) are provided in an inverter section of thepower-source substrate (92). The heat-release fins (93) are provided soas to protrude from a dorsal surface of the power-source substrate (92),and are exposed to the air supply fan chamber (36) with the heat-releasefins (93) penetrating through a dorsal plate of the electrical componentbox (90) and the frontal panel section (12) of the casing (11) (see FIG.3).

<Structure of Refrigerant Circuit>

As illustrated in FIG. 5, the refrigerant circuit (50) is a closedcircuit including the first adsorption heat exchanger (51); the secondadsorption heat exchanger (52); the compressor (53); the four-wayswitching valve (54); and the electric-operated expansion valve (55). Inthe refrigerant circuit (50), filled refrigerant circulates to perform avapor compression refrigeration cycle.

In the refrigerant circuit (50), a discharge side of the compressor (53)is connected to a first port of the four-way switching valve (54), and asuction side thereof is connected to a second port of the four-wayswitching valve (54). In addition, in the refrigerant circuit (50), thefirst adsorption heat exchanger (51), the electric-operated expansionvalve (55), and the second adsorption heat exchanger (52) aresequentially connected to each other from a third port toward a fourthport of the four-way switching valve (54).

The four-way switching valve (54) can be switched between a first state(state illustrated in FIG. 5(A)) in which the first port communicateswith the third port with the second port communicating with the fourthport, and a second state (state illustrated in FIG. 5(B)) in which thefirst port communicates with the fourth port with the second portcommunicating with the third port.

The compressor (53) is a hermetic compressor in which a compressionmechanism for compressing refrigerant and an electric motor for drivingthe compression mechanism are accommodated in a single casing. Whenchanging an alternating frequency to be supplied to the electric motorof the compressor (53) (i.e., operating frequency of the compressor(53)), the rotational speed of the compression mechanism driven by theelectric motor is changed, thereby changing the amount of refrigerantdischarged from the compressor (53) per unit time. That is, thecompressor (53) has the variable volume.

In the refrigerant circuit (50), a high-pressure sensor (101) and adischarge pipe temperature sensor (103) are attached to a pipeconnecting between the discharge side of the compressor (53) and thefirst port of the four-way switching valve (54). The high-pressuresensor (101) measures the pressure of refrigerant discharged from thecompressor (53). The discharge pipe temperature sensor (103) measuresthe temperature of refrigerant discharged from the compressor (53).

In addition, in the refrigerant circuit (50), a low-pressure sensor(102) and a suction pipe temperature sensor (104) are attached to a pipeconnecting between the suction side of the compressor (53) and thesecond port of the four-way switching valve (54). The low-pressuresensor (102) measures the pressure of refrigerant sucked into thecompressor (53). The suction pipe temperature sensor (104) measures thetemperature of refrigerant sucked into the compressor (53).

Further, in the refrigerant circuit (50), a pipe temperature sensor(105) is attached to a pipe connecting between the third port of thefour-way switching valve (54) and the first adsorption heat exchanger(51). The pipe temperature sensor (105) is arranged close to thefour-way switching valve (54) in such a pipe, and measures thetemperature of refrigerant flowing through the pipe.

<Structure of Controller>

A controller (60) is provided as a control means in the humidity controlapparatus (10). In the humidity control apparatus (10) of the presentembodiment, a microcomputer provided in the control substrate (91)serves as the controller (60).

Measured values of the room air humidity sensor (96), the room airtemperature sensor, the outdoor air humidity sensor (97), and theoutdoor air temperature sensor are inputted to the controller (60). Inaddition, measured values of the sensors (91, 92, . . . ) provided inthe refrigerant circuit (50) are inputted to the controller (60). Thecontroller (60) controls an operation of the humidity control apparatus(10) based on such inputted measured values.

In the humidity control apparatus (10), a dehumidification/ventilationoperation, a humidification/ventilation operation, a simple ventilationoperation, and a purge operation which will be described later areswitched by a control operation of the controller (60). In addition, thecontroller (60) controls actions of the dampers (41-48), the fans (25,26), the compressor (53), the electric-operated expansion valve (55),and the four-way switching valve (54) during such operations.

Operation

The humidity control apparatus (10) of the present embodimentselectively performs the dehumidification/ventilation operation, thehumidification/ventilation operation, the simple ventilation operation,and the purge operation. The humidity control apparatus (10) performsthe dehumidification/ventilation operation and thehumidification/ventilation operation as normal operations.

<Dehumidification/Ventilation Operation>

In the dehumidification/ventilation operation, the humidity controlapparatus (10) alternately repeats first and second normal actions whichwill be described later, at predetermined time intervals (e.g., 3-4minute intervals). During the dehumidification/ventilation operation,the first bypass damper (83) and the second bypass damper (84) are keptclosed.

In the dehumidification/ventilation operation, the humidity controlapparatus (10) takes outdoor air into the casing (11) through theoutdoor air suction port (24) as first air, and takes room air into thecasing (11) through the room air suction port (23) as second air.

First, the first normal action of the dehumidification/ventilationoperation will be described. As illustrated in FIG. 6, during the firstnormal action, the first room air damper (41), the second outdoor airdamper (44), the second air supply damper (46), and the first airdischarge damper (47) are opened; and the second room air damper (42),the first outdoor air damper (43), the first air supply damper (45), andthe second air discharge damper (48) are closed. During the first normalaction, the four-way switching valve (54) is set to the first state(state illustrated in FIG. 5(A)) in the refrigerant circuit (50). Thefirst adsorption heat exchanger (51) serves as a condenser, and thesecond adsorption heat exchanger (52) serves as an evaporator.

The first air flows into the outdoor air path (34) to pass through theoutdoor air filter (28), and then flows into the second heat exchangechamber (38) through the second outdoor air damper (44). Subsequently,the first air passes through the second adsorption heat exchanger (52).In the second adsorption heat exchanger (52), moisture in the first airadsorbs to the adsorbent, and then adsorption heat generated thereuponis absorbed by refrigerant. The first air dehumidified in the secondadsorption heat exchanger (52) flows into the air supply path (31)through the second air supply damper (46). After the first air passesthrough the air supply fan chamber (36), the first air is supplied tothe room through the air supply port (22).

On the other hand, the second air flows into the room air path (32) topass through the room air filter (27), and then flows into the firstheat exchange chamber (37) through the first room air damper (41).Subsequently, the second air passes through the first adsorption heatexchanger (51). In the first adsorption heat exchanger (51), moisturedesorbs from the adsorbent heated by refrigerant, and then the desorbedmoisture is imparted to the second air. The second air to which moistureis imparted in the first adsorption heat exchanger (51) flows into theair discharge path (33) through the first air discharge damper (47).After the second air passes through the air discharge fan chamber (35),the second air is discharged to the outside through the air dischargeport (21).

Next, the second normal action of the dehumidification/ventilationoperation will be described. As illustrated in FIG. 7, during the secondnormal action, the second room air damper (42), the first outdoor airdamper (43), the first air supply damper (45), and the second airdischarge damper (48) are opened; and the first room air damper (41),the second outdoor air damper (44), the second air supply damper (46),and the first air discharge damper (47) are closed. During the secondnormal action, the four-way switching valve (54) is set to the secondstate (state illustrated in FIG. 5(B)) in the refrigerant circuit (50).The first adsorption heat exchanger (51) serves as the evaporator, andthe second adsorption heat exchanger (52) serves as the condenser.

The first air flows into the outdoor air path (34) to pass through theoutdoor air filter (28), and then flows into the first heat exchangechamber (37) through the first outdoor air damper (43). Subsequently,the first air passes through the first adsorption heat exchanger (51).In the first adsorption heat exchanger (51), moisture in the first airadsorbs to the adsorbent, and then adsorption heat generated thereuponis absorbed by refrigerant. The first air dehumidified in the firstadsorption heat exchanger (51) flows into the air supply path (31)through the first air supply damper (45). After the first air passesthrough the air supply fan chamber (36), the first air is supplied tothe room through the air supply port (22).

On the other hand, the second air flows into the room air path (32) topass through the room air filter (27), and then flows into the secondheat exchange chamber (38) through the second room air damper (42).Subsequently, the second air passes through the second adsorption heatexchanger (52). In the second adsorption heat exchanger (52), moisturedesorbs from the adsorbent heated by refrigerant, and then the desorbedmoisture is imparted to the second air. The second air to which moistureis imparted in the second adsorption heat exchanger (52) flows into theair discharge path (33) through the second air discharge damper (48).After the second air passes through the air discharge fan chamber (35),the second air is discharged to the outside through the air dischargeport (21).

<Humidification/Ventilation Operation>

In the humidification/ventilation operation, the humidity controlapparatus (10) alternately repeats first and second normal actions whichwill be described later, at predetermined time intervals (e.g., 3-4minute intervals). During the humidification/ventilation operation, thefirst bypass damper (83) and the second bypass damper (84) are keptclosed.

In the humidification/ventilation operation, the humidity controlapparatus (10) takes outdoor air into the casing (11) through theoutdoor air suction port (24) as second air, and takes room air into thecasing (11) through the room air suction port (23) as first air.

First, the first normal action of the humidification/ventilationoperation will be described. As illustrated in FIG. 8, during the firstnormal action, the second room air damper (42), the first outdoor airdamper (43), the first air supply damper (45), and the second airdischarge damper (48) are opened; and the first room air damper (41),the second outdoor air damper (44), the second air supply damper (46),and first air discharge damper (47) are closed. During the first normalaction, the four-way switching valve (54) is set to the first state(state illustrated in FIG. 5(A)) in the refrigerant circuit (50). Thefirst adsorption heat exchanger (51) serves as the condenser, and thesecond adsorption heat exchanger (52) serves as the evaporator.

The first air flows into the room air path (32) to pass through the roomair filter (27), and then flows into the second heat exchange chamber(38) through the second room air damper (42). Subsequently, the firstair passes through the second adsorption heat exchanger (52). In thesecond adsorption heat exchanger (52), moisture in the first air adsorbsto the adsorbent, and then adsorption heat generated thereupon isabsorbed by refrigerant. The first air from which moisture is removed inthe second adsorption heat exchanger (52) flows into the air dischargepath (33) through the second air discharge damper (48). After the firstair passes through the air discharge fan chamber (35), the first air isdischarged to the outside through the air discharge port (21).

On the other hand, the second air flows into the outdoor air path (34)to pass through the outdoor air filter (28), and then flows into thefirst heat exchange chamber (37) through the first outdoor air damper(43). Subsequently, the second air passes through the first adsorptionheat exchanger (51). In the first adsorption heat exchanger (51),moisture desorbs from the adsorbent heated by refrigerant, and then thedesorbed moisture is imparted to the second air. The second airhumidified in the first adsorption heat exchanger (51) flows into theair supply path (31) through the first air supply damper (45). After thesecond air passes through the air supply fan chamber (36), the secondair is supplied to the room through the air supply port (22).

Next, the second normal action of the humidification/ventilationoperation will be described. As illustrated in FIG. 9, during the secondnormal action, the first room air damper (41), the second outdoor airdamper (44), the second air supply damper (46), and the first airdischarge damper (47) are opened; and the second room air damper (42),the first outdoor air damper (43), the first air supply damper (45), andthe second air discharge damper (48) are closed. During the secondnormal action, the four-way switching valve (54) is set to the secondstate (state illustrated in FIG. 5(B)) in the refrigerant circuit (50).The first adsorption heat exchanger (51) serves as the evaporator, andthe second adsorption heat exchanger (52) serves as the condenser.

The first air flows into the room air path (32) to pass through the roomair filter (27), and then flows into the first heat exchange chamber(37) through the first room air damper (41). Subsequently, the first airpasses through the first adsorption heat exchanger (51). In the firstadsorption heat exchanger (51), moisture in the first air adsorbs to theadsorbent, and then adsorption heat generated thereupon is absorbed byrefrigerant. The first air from which moisture is removed in the firstadsorption heat exchanger (51) flows into the air discharge path (33)through the first air discharge damper (47). After the first air passesthrough the air discharge fan chamber (35), the first air is dischargedto the outside through the air discharge port (21).

On the other hand, the second air flows into the outdoor air path (34)to pass through the outdoor air filter (28), and then flows into thesecond heat exchange chamber (38) through the second outdoor air damper(44). Subsequently, the second air passes through the second adsorptionheat exchanger (52). In the second adsorption heat exchanger (52),moisture desorbs from the adsorbent heated by refrigerant, and then thedesorbed moisture is imparted to the second air. The second airhumidified in the second adsorption heat exchanger (52) flows into theair supply path (31) through the second air supply damper (46). Afterthe second air passes through the air supply fan chamber (36), thesecond air is supplied to the room through the air supply port (22).

<Simple Ventilation Operation>

During the simple ventilation operation, the humidity control apparatus(10) supplies taken outdoor air (OA) to the room as supply air (SA) inunchanged form, and, at the same time, discharges taken room air (RA) tothe outside as exhaust air (EA) in unchanged form. An action of thehumidity control apparatus (10) in the simple ventilation operation willbe described with reference to FIG. 10.

During the simple ventilation operation, in the humidity controlapparatus (10), the first bypass damper (83) and the second bypassdamper (84) are opened; and the first room air damper (41), the secondroom air damper (42), the first outdoor air damper (43), the secondoutdoor air damper (44), the first air supply damper (45), the secondair supply damper (46), the first air discharge damper (47), and thesecond air discharge damper (48) are closed. Further, in the simpleventilation operation, the compressor (53) of the refrigerant circuit(50) is stopped.

During the simple ventilation operation, in the humidity controlapparatus (10), outdoor air is taken into the casing (11) through theoutdoor air suction port (24). The outdoor air flows into the outdoorair path (34) through the outdoor air suction port (24), and then flowsfrom the first bypass path (81) into the air supply fan chamber (36)through the first bypass damper (83). Subsequently, the outdoor air issupplied to the room through the air supply port (22).

Further, during the simple ventilation operation, in the humiditycontrol apparatus (10), room air is taken into the casing (11) throughthe room air suction port (23). The room air flows into the room airpath (32) through the room air suction port (23), and then flows fromthe second bypass path (82) into the air discharge fan chamber (35)through the second bypass damper (84). Subsequently, the room air isdischarged to the outside through the air discharge port (21).

<Purge Operation>

During the purge operation, each of first and second purge actions whichwill be described later is performed in the humidity control apparatus(10). A purge operation time tp which is a duration time of the first orsecond purge action is set to a value longer than a duration time of thefirst or second normal action (3-4 minutes in the present embodiment).

As illustrated in FIG. 11, during the purge operation, in the humiditycontrol apparatus (10), the first outdoor air damper (43), the secondoutdoor air damper (44), the first air discharge damper (47), and thesecond air discharge damper (48) are opened; and the first room airdamper (41), the second room air damper (42), the first air supplydamper (45), the second air supply damper (46), the first bypass damper(83), and the second bypass damper (84) are closed. During the purgeoperation, in the humidity control apparatus (10), only the airdischarge fan (25) is operated, and the air supply fan (26) is stopped.

During the purge operation, a part of outdoor air flowing into theoutdoor air path (34) flows into the first heat exchange chamber (37)through the first outdoor air damper (43), and the remaining air flowsinto the second heat exchange chamber (38) through the second outdoorair damper (44). After the air flowing into the first heat exchangechamber (37) passes through the first adsorption heat exchanger (51),such air flows into the air discharge path (33) through the first airdischarge damper (47). After the air flowing into the second heatexchange chamber (38) passes through the second adsorption heatexchanger (52), such air flows into the air discharge path (33) throughthe second air discharge damper (48). Subsequently, the air flowing intothe air discharge path (33) flows into the air discharge fan chamber(35), and then is discharged to the outside through the air dischargeport (21).

First, the first purge action will be described. During the first purgeaction, the four-way switching valve (54) is set to the first state(state illustrated in FIG. 5(A)) in the refrigerant circuit (50). Thefirst adsorption heat exchanger (51) serves as the condenser, and thesecond adsorption heat exchanger (52) serves as the evaporator. In thefirst adsorption heat exchanger (51), refrigerant releases heat tooutdoor air to be condensed. In the second adsorption heat exchanger(52), moisture in outdoor air adsorbs to the adsorbent, and thenrefrigerant absorbs adsorption heat generated thereupon to beevaporated.

In the first purge action, the capacity of the compressor (53) iscontrolled so that the refrigerant evaporation temperature in the secondadsorption heat exchanger (52) is equal to the outdoor air dew-pointtemperature; and the degree of opening of the electric-operatedexpansion valve (55) is controlled so that the degree of superheat ofrefrigerant flowing out from the second adsorption heat exchanger (52)reaches a predetermined target value. The controller (60) controls thecapacity of the compressor (53) and the degree of opening of theelectric-operated expansion valve (55). The control operation of thecontroller (60) will be described in detail later.

In this manner, moisture in air adsorbs to the second adsorption heatexchanger (52) during the first purge action. Immediately before thefirst purge action is completed, the moisture content (i.e., a ratio ofthe amount of moisture adsorbed to the adsorption heat exchanger, to theamount of moisture which is adsorbable to the adsorption heat exchanger)of the second adsorption heat exchanger (52) becomes equal to or greaterthan 90%. In the dehumidification/ventilation operation or thehumidification/ventilation operation, the moisture content of the secondadsorption heat exchanger (52) immediately before the first normalaction is completed is approximately 70%. Thus, the moisture content ofthe second adsorption heat exchanger (52) immediately before thecompletion of the first purge action is greater than that immediatelybefore the completion of the first normal action.

The humidity control apparatus (10) is for controlling the air humidity,and therefore adsorbent having higher water (H₂O) adsorption capacity isused in the humidity control apparatus (10). In addition, the amount ofwater vapor in air is much greater than that of odor material, andtherefore the partial pressure of water vapor in air is much higher thanthat of odor material. Thus, water has higher adsorbability to theadsorbent of the adsorption heat exchanger (51, 52) as compared to thatof odor material.

This allows water vapor having the higher adsorbability to the adsorbentto preferentially adsorb to the adsorbent when the moisture content ofthe second adsorption heat exchanger (52) is increased by the firstpurge action, thereby desorbing odor material such as ammonia, whichgenerally adsorbs to the adsorbent, from the adsorbent. The odormaterial desorbed from the second adsorption heat exchanger (52) isdischarged to the outside together with outdoor air passing through thesecond adsorption heat exchanger (52).

Next, the second purge action will be described. During the second purgeaction, the four-way switching valve (54) is set to the second state(state illustrated in FIG. 5(B)) in the refrigerant circuit (50). Thesecond adsorption heat exchanger (52) serves as the condenser, and thefirst adsorption heat exchanger (51) serves as the evaporator. In thesecond adsorption heat exchanger (52), refrigerant releases heat tooutdoor air to be condensed. In the first adsorption heat exchanger(51), moisture in outdoor air adsorbs to the adsorbent, and thenrefrigerant absorbs adsorption heat generated thereupon to beevaporated.

In the second purge action, the capacity of the compressor (53) iscontrolled so that the refrigerant evaporation temperature in the firstadsorption heat exchanger (51) is equal to the outdoor air dew-pointtemperature; and the degree of opening of the electric-operatedexpansion valve (55) is controlled so that the degree of superheat ofrefrigerant flowing out from the first adsorption heat exchanger (51)reaches a predetermined target value. The controller (60) controls thecapacity of the compressor (53) and the degree of opening of theelectric-operated expansion valve (55). The control operation of thecontroller (60) will be described in detail later.

In this manner, moisture in air adsorbs to the first adsorption heatexchanger (51) during the second purge action. Immediately before thesecond purge action is completed, the moisture content of the firstadsorption heat exchanger (51) becomes equal to or greater than 90%. Inthe dehumidification/ventilation operation or thehumidification/ventilation operation, the moisture content of the firstadsorption heat exchanger (51) immediately before the second normalaction is completed is approximately 70%. Thus, the moisture content ofthe first adsorption heat exchanger (51) immediately before thecompletion of the second purge action is greater than that immediatelybefore the completion of the first normal action.

As described above, water has the higher adsorbability to the adsorbentof the adsorption heat exchanger (51, 52) as compared to that of odormaterial. This allows water vapor having the higher adsorbability to theadsorbent to preferentially adsorb to the adsorbent when the moisturecontent of the first adsorption heat exchanger (51) is increased by thesecond purge action, thereby desorbing odor material such as ammonia,which generally adsorbs to the adsorbent, from the adsorbent. The odormaterial desorbed from the first adsorption heat exchanger (51) isdischarged to the outside together with outdoor air passing through thefirst adsorption heat exchanger (51).

During the purge operation, in the humidity control apparatus (10), theair supply fan (26) is stopped, thereby, as a general rule, notcirculating air in the air supply fan chamber (36) (see FIG. 11). On theother hand, the compressor (53) is operated in the refrigerant circuit(50) during the purge operation. The inverter section of thepower-source substrate (92) generates heat, and therefore it isnecessary to release the heat generated in the inverter section, throughthe heat-release fins (93). When the ambient temperature of the humiditycontrol apparatus (10) is not so high, the heat-release amount from theheat-release fins (93) is sufficiently ensured even in stagnant airinside the air supply fan chamber (36). However, when the ambienttemperature of the humidity control apparatus (10) rises to some extent,the heat-release amount from the heat-release fins (93) cannot beensured, thereby causing damage in the inverter section.

The humidity control apparatus (10) of the present embodiment performsan action for enhancing the heat release from the heat-release fins (93)when it is about to cause insufficiency of the heat-release amount fromthe heat-release fins (93) during the purge operation. Such an actionwill be described hereinafter with reference to FIG. 12.

The humidity control apparatus (10) of the present embodiment istypically installed in a space above a ceiling, and environment in sucha space is rather close to outdoor environment. When the outdoor airtemperature detected by the outdoor air temperature sensor exceeds apredetermined reference value (e.g., 11° C.) during the purge operation,the humidity control apparatus (10) determines that there is apossibility to cause the insufficiency of the heat-release amount fromthe heat-release fins (93), and then opens the first bypass damper (83).During the purge operation, the pressure of the outdoor air path (34)positioned on a suction side of the air discharge fan (25) is negative.This allows outdoor air to flow into the air supply fan chamber (36)through the air supply port (22) and the air supply fan (26) which isstopped, when opening the first bypass damper (83). Subsequently, theoutdoor air passes through the first bypass damper (83), and then flowsinto the outdoor air path (34) through the first bypass path (81). Inthis manner, when opening the first bypass damper (83) during the purgeoperation, air flows in the air supply fan chamber (36), therebyenhancing the heat release from the heat-release fins (93).

Control Operation of Controller

The control operation performed by the controller (60) will bedescribed. The control operation during the purge operation will bemainly described hereinafter.

The controller (60) sums up the operation time of thedehumidification/ventilation operation and of thehumidification/ventilation operation (i.e., normal operations), andpermits the humidity control apparatus (10) to execute the purgeoperation when the summation of the operation time reaches apredetermined reference value. Specifically, the controller (60) permitsthe humidity control apparatus (10) to execute the purge operation whenthe summation of the operation time of the normal operations exceeds 12hours, and a switch of a remote controller of the humidity controlapparatus (10) is “OFF.” The humidity control apparatus (10) may beconstantly operated, and the switch of the remote controller may not be“OFF.” In such a case, the controller (60) forcibly permits the humiditycontrol apparatus (10) to execute the purge operation when the summationof the operation time of the normal operations exceeds 120 hours.

The control operation performed by the controller (60) during the purgeoperation will be described with reference to the flow chart of FIG. 13.

At step ST10, when satisfying conditions for executing the purgeoperation, the controller (60) opens the first outdoor air damper (43),the second outdoor air damper (44), the first air discharge damper (47),and the second air discharge damper (48), and closes the remainingdampers. Subsequently, at step ST11, the controller (60) starts the airdischarge fan (25). At this point, the air supply fan (26) is stopped.

At step ST12, the controller (60) sets the purge operation time tp whichis the duration time of the first or second purge action. At this point,the controller (60) controls the purge operation time tp depending onthe outdoor air absolute humidity. Specifically, the controller (60)calculates the outdoor air absolute humidity by using the outdoor airtemperature measured by the outdoor air temperature sensor, and theoutdoor air relative humidity measured by the outdoor air humiditysensor (97). The controller (60) sets the value of the purge operationtime tp within a range of greater than or equal to 10 minutes and lessthan or equal to 50 minutes so that the purge operation time tp becomeslonger as the outdoor air absolute humidity decreases.

Then, at step ST13, the controller (60) starts the compressor (53). Atthis point, suppose that the four-way switching valve (54) is in thefirst state (state illustrated in FIG. 5(A)) at the time of starting thecompressor (53). In such a case, the first purge action is executed whenthe compressor (53) is started. Subsequently, at step ST14, thecontroller (60) controls the capacity of the compressor (53) and thedegree of opening of the electric-operated expansion valve (55). Thecontroller (60) continuously controls the capacity of the compressor(53) and the degree of opening of the electric-operated expansion valve(55) until the process reaches step ST18 which will be described later.

Specifically, at step ST 14, the controller (60) controls the operatingfrequency of the compressor (53) so that the refrigerant evaporationtemperature Te in the second adsorption heat exchanger (52) serving asthe evaporator is equal to the outdoor air dew-point temperature Todew.At this point, the controller (60) calculates the evaporationtemperature Te by using the measured value of the low-pressure sensor(102), and calculates the outdoor air dew-point temperature by using themeasured values of the outdoor air temperature sensor and of the outdoorair humidity sensor (97). The controller (60) increases the operatingfrequency of the compressor (53) if the evaporation temperature Te ishigher than the dew-point temperature Todew; and decreases the operatingfrequency of the compressor (53) if the evaporation temperature Te islower than the dew-point temperature Todew.

In addition, at step ST 14, the controller (60) controls the degree ofopening of the electric-operated expansion valve (55) so that the degreeof superheat of refrigerant flowing out from the second adsorption heatexchanger (52) which serves as the evaporator reaches the predeterminedtarget value (e.g., 3° C.). At this point, the controller (60)calculates the degree of superheat SH of refrigerant by using the suckedrefrigerant pressure of the compressor (53), which is measured by thelow-pressure sensor (102), and the sucked refrigeration temperature ofthe compressor (53), which is measured by the suction pipe temperaturesensor (104). The controller (60) increases the degree of opening of theelectric-operated expansion valve (55) if the calculated degree ofsuperheat SH of refrigerant is higher than the target value; anddecreases the degree of opening of the electric-operated expansion valve(55) if the calculated degree of superheat SH of refrigerant is lowerthan the target value.

Subsequently, at step ST 15, the controller (60) compares between theduration time of the first purge action (i.e., time elapsed after thecompressor (53) is started at step ST 13) and the purge operation timetp which is set at step ST 12. If the duration time of the first purgeaction does not reach the purge operation time tp, the controller (60)remains in a standby state and continues the first purge action. On theother hand, if the duration time of the first purge action reaches thepurge operation time tp, the controller (60) proceeds to step ST 16, andswitches the four-way switching valve (54) from the first state to thesecond state (state illustrated in FIG. 5(B)). That is, the controller(60) completes the first purge action, and starts the second purgeaction.

As described above, even after the start of the second purge action, thecontroller (60) continuously controls the compressor (53) and theelectric-operated expansion valve (55). That is, the controller (60)controls the operating frequency of the compressor (53) so that therefrigerant evaporation temperature Te in the first adsorption heatexchanger (51) which serves as the evaporator is equal to the outdoorair dew-point temperature Todew. In addition, the controller (60)controls the degree of opening of the electric-operated expansion valve(55) so that the degree of superheat of refrigerant flowing out from thefirst adsorption heat exchanger (51) which serves as the evaporatorreaches the predetermined target value.

Subsequently, at step ST 17, the controller (60) compares between theduration time of the second purge action (i.e., time elapsed after thefour-way switching valve (54) is switched at step ST 16) and the purgeoperation time tp which is set at step ST 12. If the duration time ofthe second purge action does not reach the purge operation time tp, thecontroller (60) remains in a standby state and continues the secondpurge action. On the other hand, if the duration time of the secondpurge action reaches the purge operation time tp, the controller (60)proceeds to step ST 18 to stop the compressor (53).

Next, at step ST 19, the controller (60) stops the air discharge fan(25). Further, at step ST 20, the controller (60) closes the firstoutdoor air damper (43), the second outdoor air damper (44), the firstair discharge damper (47), and the second air discharge damper (48)(i.e., dampers opened at step ST 10).

Then, the controller (60) completes the purge operation. At this point,in the controller (60), the operation time of thedehumidification/ventilation operation and thehumidification/ventilation operation, which has been summed up to thatpoint, is reset to zero.

In addition, the controller (60) performs the purge operation as a testoperation immediately after the humidity control apparatus (10) isinstalled. Environment where the humidity control apparatus (10) isstored before its installation is various, and it is conceivable thatodor material may enter the casing (11) of the humidity controlapparatus (10) during storage, and such odor material may adsorb to theadsorption heat exchangers (51, 52). Thus, the purge operation performedby the humidity control apparatus (10) immediately after theinstallation of the humidity control apparatus (10) ensures a state inwhich odor material is not adsorbed to the adsorption heat exchangers(51, 52), thereby preventing the odor material from entering the roomduring the subsequent dehumidification/ventilation operation orhumidification/ventilation operation.

Advantages of Embodiment

According to the present embodiment, the humidity control apparatus (10)performs the purge operation to increase the moisture content of theadsorption heat exchanger (51, 52), thereby desorbing odor material fromthe adsorption heat exchanger (51, 52). The amount of odor materialadsorbed to the adsorption heat exchanger (51, 52) can be reduced by theoperation of the humidity control apparatus (10) itself without amaintenance person going and working at an installation site of thehumidity control apparatus (10). This prevents odor material desorbedfrom the adsorption heat exchangers (51, 52) from being supplied to theroom together with humidity-controlled air during the normal operations,thereby ensuring improvement of comfort in the room.

During the purge operation of the present embodiment, the moisturecontent of the adsorption heat exchanger (51, 52) reaches the valueequal to or greater than the moisture content of the adsorption heatexchanger (51, 52) during the normal operation. That is, during thenormal operation subsequent to the purge operation, the moisture contentof the adsorption heat exchanger (51, 52) does not exceed the valueduring the purge operation. This ensures reduction of desorption of odormaterial from the adsorption heat exchangers (51, 52) during thedehumidification/ventilation operation or the humidification/ventilationoperation, thereby, also in this regard, ensuring the comfort in theroom.

In the present embodiment, the capacity of the compressor (53) of therefrigerant circuit (50) is controlled so that the refrigerantevaporation temperature in the adsorption heat exchanger (51, 52)operating as the evaporator during the purge operation is equal to thedew-point temperature of air passing through such an adsorption heatexchanger (51, 52). This reduces the surface temperature of theadsorption heat exchanger (51, 52) as much as possible within a range inwhich dew condensation is not caused on the surface of the adsorptionheat exchanger (51, 52) serving as the evaporator, during the purgeoperation. Consequently, it is unnecessary to dispose drain water due tothe dew condensation on the adsorption heat exchanger (51, 52), and theamount of moisture adsorbed to the adsorption heat exchanger (51, 52)during the purge operation can be maximized.

In the present embodiment, during the purge operation, the humiditycontrol apparatus (10) supplies outdoor air to the first adsorption heatexchanger (51) and the second adsorption heat exchanger (52), anddischarges the outdoor air passing through the adsorption heatexchangers (51, 52) to the outside. That is, the humidity controlapparatus (10) performs the purge operation without sucking air from theroom, and blowing off air to the room. Thus, according to the presentembodiment, the purge operation can be performed without effects on theroom environment.

In the present embodiment, the time for which moisture in air adsorbs tothe adsorption heat exchanger (51, 52) during the purge operation (i.e.,purge operation time tp) is longer than the time for which moisture inair adsorbs to the adsorption heat exchanger (51, 52) during the normaloperation. Thus, according to the present embodiment, this ensures themoisture content of the adsorption heat exchanger (51, 52) during thepurge operation, which is greater than the moisture content of theadsorption heat exchanger (51, 52) during the normal operation, therebyensuring removal of odor material from the adsorption heat exchanger(51, 52) by the purge operation.

In the present embodiment, the purge operation time tp is controlleddepending on the absolute humidity of outdoor air from which moisture isimparted to the adsorption heat exchanger (51, 52) during the purgeoperation. This ensures an increase in the moisture content of theadsorption heat exchanger (51, 52) in spite of the outdoor-air stateduring the purge operation, thereby ensuring the removal of odormaterial from the adsorption heat exchanger (51, 52).

First Variation of Embodiment

In a refrigerant circuit (50) of the present embodiment, a supercriticalcycle may be performed, in which a high pressure of a refrigerationcycle is set to a value higher than a critical pressure of refrigerant.In such a case, one of a first adsorption heat exchanger (51) and asecond adsorption heat exchanger (52) operates as a gas cooler, and theother operates as an evaporator.

Second Variation of Embodiment

In a humidity control apparatus (10) of the present embodiment,adsorbent deposited on a first adsorption heat exchanger (51) and asecond adsorption heat exchanger (52) is heated or cooled byrefrigerant, but the adsorbent may be heated or cooled by supplying coldor hot water to the first adsorption heat exchanger (51) and the secondadsorption heat exchanger (52).

The foregoing embodiments have been set forth merely for purposes ofpreferred examples in nature, and are not intended to limit the scope,applications, and use of the invention.

INDUSTRIAL APPLICABILITY

As described above, the present invention is useful in a humiditycontrol apparatus for controlling air humidity by using adsorbent.

1. A humidity control apparatus including adsorption members (51, 52)with adsorbent, and controlling air humidity by exposing taken air tothe adsorbent of the adsorption members (51, 52), wherein operations areselectively executed, which are normal operations in which air, humidityof which is controlled when passing through the adsorption member (51,52), is supplied to a room; and a purge operation in which, in order todesorb odor material from the adsorption member (51, 52), moisture intaken air adsorbs to the adsorption member (51, 52) to obtain a moisturecontent of the adsorption member (51, 52) equal to or greater than amaximum value of a moisture content of the adsorption member (51, 52)during the normal operation.
 2. The humidity control apparatus of claim1, wherein adsorption heat exchangers (51, 52) with adsorbent depositedon surfaces thereof are provided as the adsorption members; theadsorption heat exchangers (51, 52) are connected to each other to forma heat-transfer medium circuit (50) in which heat-transfer mediumcirculates; and the heat-transfer medium circuit (50) performs an actionin which heat-transfer medium for cooling is supplied to the adsorptionheat exchanger (51, 52) in order to adsorb moisture in air to theadsorption heat exchanger (51, 52), and an action in which heat-transfermedium for heating is supplied to the adsorption heat exchanger (51, 52)in order to desorb moisture from the adsorption heat exchanger (51, 52).3. The humidity control apparatus of claim 2, wherein a refrigerantcircuit (50) performing a refrigeration cycle by circulating refrigerantis provided as the heat-transfer medium circuit; and, during the purgeoperation, in the refrigerant circuit (50), refrigerant circulates sothat the adsorption heat exchanger (51, 52) to which moisture in airadsorbs serves as an evaporator, and a capacity of a compressor (53) iscontrolled so that a refrigerant evaporation temperature in theadsorption heat exchanger (51, 52) is equal to a dew-point temperatureof air passing through the adsorption heat exchanger (51, 52).
 4. Thehumidity control apparatus of claim 3, wherein, during the purgeoperation, in the refrigerant circuit (50), a degree of opening of anexpansion valve (55) is controlled so that a degree of superheat ofrefrigerant at an outlet of the adsorption heat exchanger (51, 52)serving as the evaporator is constant.
 5. The humidity control apparatusof claim 2, wherein a refrigerant circuit (50) performing arefrigeration cycle by circulating refrigerant is provided as theheat-transfer medium circuit; the refrigerant circuit (50) includes afirst adsorption heat exchanger (51) and a second adsorption heatexchanger (52) as adsorption members, and is switchable between a statein which the first adsorption heat exchanger (51) serves as a heatradiator, and the second adsorption heat exchanger (52) serves as theevaporator; and a state in which the second adsorption heat exchanger(52) serves as the heat radiator, and the first adsorption heatexchanger (51) serves as the evaporator; during the normal operation,actions are alternately repeated, which are a first normal action inwhich second air is supplied to the first adsorption heat exchanger (51)serving as the heat radiator, and first air is supplied to the secondadsorption heat exchanger (52) serving as the evaporator, and a secondnormal action in which second air is supplied to the second adsorptionheat exchanger (52) serving as the heat radiator, and first air issupplied to the first adsorption heat exchanger (51) serving as theevaporator; and one of the first dehumidified air and the secondhumidified air is supplied to the room, and the other is discharged tooutside; and during the purge operation, each of actions is performed,which are a first purge action in which outdoor air is supplied to thefirst adsorption heat exchanger (51) serving as the heat radiator, andto the second adsorption heat exchanger (52) serving as the evaporator,and a second purge action in which outdoor air is supplied to the secondadsorption heat exchanger (52) serving as the heat radiator, and to thefirst adsorption heat exchanger (51) serving as the evaporator; and theoutdoor air passing through the first adsorption heat exchanger (51) andthe second adsorption heat exchanger (52) is discharged to the outside.6. The humidity control apparatus of claim 5, wherein the first andsecond normal actions are alternately performed at predetermined timeintervals during the normal operation; the first and second purgeactions are performed for a predetermined period of time during thepurge operation; and a duration time of each purge action during thepurge operation is longer than a duration time of each normal actionduring the normal operation.
 7. The humidity control apparatus of claim1, wherein a duration time of the purge operation is controlled so as toincrease as an absolute humidity of air supplied to the adsorptionmember (51, 52) during the purge operation becomes lower.
 8. Thehumidity control apparatus of claim 1, wherein the purge operation isperformed every time a summation of time for which the normal operationsare performed reaches a predetermined reference value.